Switch chrome_elf exception handling from breakpad to crashpad

Relanding this patch with windows gypi build fixes.

Switch chrome_elf exception handling from breakpad to crashpad.

Changes in this patch are as below:
1. chrome_elf: Removing breakpad and corresponding exception initialization using breakpad. Registering crashpad as the exception handling mechanism in chrome_elf.
   We continue to handle exceptions in chrome_elf in DllMain and in the blacklist interception code as before, i.e. we use crashpad to grab the dump and pass
   the exception to the next handler in the chain. I also added support in chrome_elf to not initialize crashpad if it is being loaded in some tests. For e.g. the
   ELFImportsTest. This is via the exe name check.

2. chrome.exe:- Removing crashpad exception registration. We need to retrieve current exception reports information from chrome_elf instead of chrome.

3. Intercept the SetUnhandledExceptionFilter API in chrome_elf via IAT patching on the exe and disallow the call. This is to prevent CRT from overwriting crashpads exception
   filter. I added a TODO to see if we can use EAT patching or possibly sidestep if we can support 64 bit with it.

4. Changed the browser lib target to depend on chrome_elf:blacklist instead of chrome_elf. This	prevents chrome_elf from being implicitly loaded in processes other
   than chrome.exe

5. Changed child_process_logging_win.cc to set the crash key trampolines from chrome_elf instead of chrome.exe.

6. Changed the blacklist target in blacklist.gypi to depend on the chrome_elf_common target. Previously this dependency came in through the chrome_elf_breakpad target which has been deleted in this patch set.

BUG=604923, crashpad:106, 568664
TBR=sky

Review-Url: https://codereview.chromium.org/2114533002
Cr-Commit-Position: refs/heads/master@{#403519}
23 files changed